Sodium laureth sulfate (SLES), an accepted contraction of sodium lauryl

ether In organic chemistry, ethers are a class of compounds that contain an ether group, a single oxygen atom bonded to two separate carbon atoms, each part of an organyl group (e.g., alkyl or aryl). They have the general formula , where R and R� ...

sulfate, also called sodium alkylethersulfate, is an

anion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conven ...

detergent A detergent is a surfactant or a mixture of surfactants with Cleanliness, cleansing properties when in Concentration, dilute Solution (chemistry), solutions. There are a large variety of detergents. A common family is the alkylbenzene sulfonate ...

and

surfactant Surfactants are chemical compounds that decrease the surface tension or interfacial tension between two liquids, a liquid and a gas, or a liquid and a solid. The word ''surfactant'' is a Blend word, blend of "surface-active agent", coined in ...

found in many personal care products (

soap Soap is a salt (chemistry), salt of a fatty acid (sometimes other carboxylic acids) used for cleaning and lubricating products as well as other applications. In a domestic setting, soaps, specifically "toilet soaps", are surfactants usually u ...

shampoo Shampoo () is a hair care product, typically in the form of a viscous liquid, that is formulated to be used for cleaning (scalp) hair. Less commonly, it is available in solid bar format. (" Dry shampoo" is a separate product.) Shampoo is use ...

toothpaste Toothpaste is a paste or gel dentifrice that is used with a toothbrush to clean and maintain the aesthetics of Human tooth, teeth. Toothpaste is used to promote oral hygiene: it is an abrasive that aids in removing dental plaque and food from th ...

, etc.) and for industrial uses. SLES is an inexpensive and very effective

foaming agent A foaming agent is a material such as a surfactant or a blowing agent that facilitates the formation of foam. A surfactant, when present in small amounts, reduces surface tension of a liquid (reduces the work needed to create the foam) or increas ...

.Kurt Kosswig,"Surfactants" in ''Ullmann's Encyclopedia of Industrial Chemistry'', Wiley-VCH, 2005, Weinheim. SLES,

sodium lauryl sulfate Sodium dodecyl sulfate (SDS) or sodium lauryl sulfate (SLS), sometimes written sodium laurilsulfate, is an organic compound with the formula and structure . It is an anionic surfactant used in many cleaning and hygiene products. This compound ...

(SLS), ammonium lauryl sulfate (ALS), and sodium pareth sulfate are

s that are used in many cosmetic products for their cleaning and emulsifying properties. It is derived from

palm kernel oil Palm kernel oil is an edible plant oil derived from the kernel of the oil palm tree ''Elaeis guineensis''. It is related to two other edible oils: ''palm oil'', extracted from the fruit pulp of the oil palm, and ''coconut oil'', extracted from ...

coconut oil Coconut oil (or coconut fat) is an edible oil derived from the kernels, meat, and milk of the coconut palm fruit. Coconut oil is a white solid fat below around , and a clear thin liquid oil at higher temperatures. Unrefined varieties have a disti ...

. In herbicides, it is used as a surfactant to improve absorption of the herbicidal chemicals and reduces time the product takes to be rainfast, when enough of the herbicidal agent will be absorbed. Its chemical formula is . Sometimes the number represented by ''n'' is specified in the name, for example laureth-2 sulfate. The product is heterogeneous in the number of ethoxyl groups, where ''n'' is the mean. Laureth-3 sulfate is the most common one in commercial products.

Production

SLES is prepared by

ethoxylation In organic chemistry, ethoxylation is a chemical reaction in which ethylene oxide () adds to a substrate. It is the most widely practiced alkoxylation, which involves the addition of epoxides to substrates. In the usual application, alcoh ...

of dodecyl alcohol, which is produced industrially from

. The resulting ethoxylate is converted to a half ester of sulfuric acid, which is neutralized by conversion to the

sodium Sodium is a chemical element; it has Symbol (chemistry), symbol Na (from Neo-Latin ) and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 element, group 1 of the peri ...

salt In common usage, salt is a mineral composed primarily of sodium chloride (NaCl). When used in food, especially in granulated form, it is more formally called table salt. In the form of a natural crystalline mineral, salt is also known as r ...

. The related surfactant

or SLS (also known as sodium dodecyl sulfate or SDS) is produced similarly, but without the ethoxylation step. SLS and ammonium lauryl sulfate (ALS) are commonly used alternatives to SLES in consumer products.

Safety

Tests in the US indicate that it is safe for consumer use. The Australian government's

Department of Health and Ageing The Australian Federal Department of Health and Ageing was an Australian government department that existed between November 2001 and September 2013. The department was created after the 2001 federal election from the Department of ...

and its National Industrial Chemicals Notification and Assessment Scheme (NICNAS) have determined that SLES does not react with DNA.

Irritation

Like many other

s, SLES is an irritant. It has been shown that SLES causes eye or skin irritation in experiments conducted on animals and humans. The related surfactant SLS is also a known irritant.

1,4-Dioxane contamination

Products containing SLES can be contaminated with up to 300 ppm of 1,4-dioxane, a by-product of SLES production. 1,4-Dioxane is classified by the

International Agency for Research on Cancer The International Agency for Research on Cancer (IARC; ) is an intergovernmental agency forming part of the World Health Organization of the United Nations. Its role is to conduct and coordinate research into the causes of cancer. It also cance ...

as a Group 2B carcinogen: ''possibly carcinogenic to humans''. The

United States Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respo ...

(FDA) recommends that these levels be monitored, and encourages manufacturers to remove 1,4-dioxane, though it is not required by federal law.FDA/CFSAN--Cosmetics Handbook Part 3: Cosmetic Product-Related Regulatory Requirements and Health Hazard Issues
Prohibited Ingredients and other Hazardous Substances: 9. Dioxane
/ref>

References

External links